UFO sighting at Rishra Hooghly

On June 2015 one evening I was watering the plants on my terrace. After watering the plants on the eastern side of the terrace then watered the northern side pots and then when I was facing and watering the plant pots on the western side of the terrace, on which side our house faces, I raised my head and looked on the left side (which is to south) and saw a small 10 watt dim bulb size light coming towards north sky. As the Barrackpur Indian Air Force Runway is just 5 km north-east of my house and the Kolkata International Airport just 15 km south-east of my house, initially I had thought that it might be a small aircraft or Mi 17 helicopter very far (IAF Mi17 helicopter flies all day over my house). But the light which was travelling very fast towards north suddenly decreased acceleration and was still in the sky, without any noise. A helicopter or plane cannot do that. Was it using a different technology? An anti gravity technology that allows it to hover? And how did it achieve so much acceleration without creating sound? Certainly no fossil fuel was used, because even the smaller planes or helicopters creates lot of sound. I did talk about the incident but as human nature goes most thought of it as a joke. But somehow I knew it was some technology out of earth. Maybe because I had read Eric Von Daniken's books on astronauts and other life forms visiting Earth since time immemorial, that I had no trouble believing in it. Also my grandfather in 1994 or 95 had told me that while reading a book sitting on a tool in his terrace at Burdwan he had seen a shining disk which was rotating and was as bright as the sun. But it was 5:30 and the sun was about to set and the shining rotating disk was seen by him on the northern sky. So he immediately knew it cannot be the sun. He had also regretted that if he had a camera and could have managed to take a photo of that object, then that photo could have fetched him huge money from German magazine and newspaper. (A German scientist who had an ancestral house at Burdwan, was his friend). I would have not taken the trouble of writing this blog had I not watched these 2 vieos on Youtube today. The links as follows -
https://youtu.be/iQH11GW7w8Q
https://youtu.be/hwwtxHEI0Wc